NOVA Online | Mysteries of the Nile | An Archaeologist's Perspective

An Archaeologist's Perspective (Q&A)

Following the broadcast of "Secrets of Lost Empires: Obelisk" On May 19 1998, archaeologist Mark Lehner fielded questions sent in by Web site visitors about obelisks and ancient Egypt in general. Take a look, and see what Lehner had to say. If you'd like to send in your own theory, or see what people are suggesting now that our obelisk team is back in Egypt on their second attempt, visit "How Would You Do It?"

Complete Questions and Answers | List of Questions

Question: In the NOVA about Stonehenge, the A-frame you made had the ropes that the volunteers pull higher than the ropes connected to the rock, and in the NOVA about the obelisk, you had the ropes at the same level. Wouldn't it be easier if you had the A-frame like in the NOVA about Stonehenge? ~Justin

Answer: Yes, it would. That's one of the lessons we learned out of both these operations. If the A-frame had been higher, and in fact even if the pullers in the obelisk operation had been higher, we might have gotten more lift out of the pole. As it was in the obelisk operation, the pole wasn't getting much lift at all, it was actually probably pulling the obelisk down into the turning groove.

Question: Will it be possible to hear a discussion of the obelisk containing the code of Hammurabi? Is the obelisk containing the code of Hammurabi still in existence? ~J.T.

Answer: The code of Hammurabi is on a much smaller obelisk. This is not my area of specialty, but it's not what they raised in any quantity. It contains cuneiform text.

Question: Would the Egyptians have used elephant power to raise the obelisk? They were excellent builders and had a great understanding of mechanics. It seems to me that elephants would be cheaper and less troublesome than slaves, as well as pound per pound much more powerful than men. ~Marshall

Answer: No, the evidence is that elephants did not exist in Egypt after the late Dynastic period or into the Dynastic period, say after 2900 B.C. So they were never common, although they may have been brought in by pharaohs like Thomoses III. He also created a zoo in the Karnak temple. Elephants were never common in Egypt like they are in India today, so they were never part of the construction. It is the case that cows were used and we do have evidence of that, but in moving something as big as the obelisk it was most probably people power.

Question: What was the general attitude of the 200 men who were working on site, the common man's attitude to this project, if you will? ~James

Answer: Well, the attitude of the 200 men working on our site was one of great enthusiasm. They were really into this operation. There was a real team spirit. I don't know if you can notice it in the film, but when the obelisk was successfully tipped and then slid down into a turning groove, the men from Luxor, who are mostly around the obelisk itself, began chanting "Luxor, Luxor, Luxor!" And all the men from Aswan, who were mostly the pullers, began chanting "Aswan, Aswan, Aswan!" So there was a real esprit de corps, a real camaraderie among the team. It was almost like a great sports event where they had won a championship.

Question: What was the time period you had to raise the obelisk? ~Grayson

Answer: Well, I think all told, the whole production was about three weeks. So a good week of that was taken up with preparations of various kinds. To raise the obelisk itself, we maybe had two weeks. And so it was a very short time period indeed. That's why we think with more time, we probably would have successfully gotten it up, but unfortunately, modern production schedules don't match ancient pharaohs' schedules.

Question: Why not use a pulley on level ground to gain a mechanical advantage for the pullers? ~Travis

Answer: Well, we often get questions of why we don't use pulleys in pyramid building or obelisk raising, and one very critical piece of information here was given by Roger Hopkins on the production. He said a pulley is only as good as a wheel is as good as its axle. In other words, they didn't have iron or steel at this period, and for a pulley really to work, you need a very strong axle. A pulley is essentially a wheel. For wooden pulleys or various other kinds of pulleys it just didn't work. They probably had something like the pulley as early as the Middle Kingdom, several hundred years before the New Kingdom, but it was not as powerful as it needed to be if they made it out of steel or iron.

Question: Why not anchor the base in the groove stone with a team pulling in the opposite direction to the lift? ~Kevin

Answer: Well, if I understand the question correctly, this is essentially what Martin Isler had envisioned, that you basically bring the obelisk up to the turning groove and you park it in the turning groove, and then you have men pulling it to an upright position after it's been leveled high enough so the pull has some effect. That's one of the two principal ideas for how you raise an obelisk. And there are definite problems with that. It worked for Martin Isler's obelisk, which was two to three tons, but for a 450-ton obelisk, you don't have that much more room to do levering on the point end of the obelisk. And as you saw on the film, we have a great deal of difficulty just getting a 40-ton obelisk levered high enough so that the pull has some effect. It would have been exponentially more problematic for a 450-ton obelisk.

Question: Do you think having more people pulling to try to erect the obelisk would have made a difference? ~Andrea

Answer: Well, I don't think more people pulling would have made a difference, unless we had gotten them to a higher platform, where the pull had more lift, or unless we had used our A-frame on a higher platform so that the ropes would have had more lift. Otherwise, I think what was happening in our situation is that the pullers were simply pulling the obelisk down towards the obelisk rather than getting their lift out of the pull.

Question: Have you considered a rising road bed level on the lever side of the obelisk, also decreasing the height of the A-frame and extending ropes, as the pharaohs had many more than 200 willing participants? ~Pete

Answer: Well, it certainly is true that they had more willing or unwilling participants than 200. They could have had as many participants as they wanted. The thing is, the whole arena of operation is restricted by the space that is there in front of the great temple pylons or gateways, like in front of the Luxor temple. But any number of configurations can be tried, it just has to fit within the space available, and that includes the number of pullers. For example, in the Luxor temple, where Ramses raised two of the biggest obelisks of all times, and only one remains today, it is not that far from the temple to the river. And we know that the men were pulling on the river side because the turning groove is on the land side. So you've got to take all these different factors into consideration, and they set limitations for how many men, the length of the roadway, and therefore, the height of the roadway and so on.

Question: How many finished obelisks are there in existence now? Were they cut from the same type of stone? Is there any indication about who the sculptors were? ~Jeunesse

Answer: Well, I simply don't know off the top of my head what the total number of finished obelisks may be in Egypt today, although that might be known in the book, "Obelisks, the Skyscrapers of Ancient Egypt." I'm sure we could look it up. The obelisks are mostly of red granite. But there are a number of obelisks from other types of stone. There are a few limestone ones, sandstone ones, and some quartzite obelisks. The makers of the obelisks, that is the overseers in charge and the craftsmen, never signed their work, and this was usually the case in ancient Egypt, that the fine craftsmen, whatever the masterpiece may be, including a masterpiece statue of a pharaoh, they never signed their work. It was not so much the creation of any one of a particular artist, it was more of divine object that was created on behalf of this divine king. It is the case that there are only about four or five obelisks still standing in Egypt in their original sites.

Question: You need to raise the obelisk on a ramp to a height where the center of gravity is at its final height, then secure a frame at the center of gravity, which can be used to pivot the obelisk, which is now balanced at its center of gravity to a vertical position. ~Richard

Answer: Well, that's a good suggestion. I think what the questioner is suggesting is that the frame be actually on the obelisk side of the erection pit rather than the A-frame that we put on the pulling side of the erection pit. Now, if you had some kind of a frame or a windblast kind of tying off of the obelisk, like Martin Isler had, then you could just simply pivot it, you know. That could work. I would be interested in the details of how the frame would be composed. Would it be wood? How would the turning be effected? Again, we don't have pulleys, we don't have cogs, we don't have gears. So it's an interesting suggestion, we need more details.

Question: How different was the scale of the pyramid building from the scale of the obelisk quarrying and raising? ~Mark

Answer: The scale of pyramid building is totally different than that of obelisk raising, especially if you're talking about the early period of pyramid building, the first three or four generations. That's when they built the gigantic pyramids. That was a humongous task. It was building a geological structure with human power, you know, something on the scale of a small mountain. The obelisk is more of a single object and a single event. The obelisk is no less daring, because you have this huge piece of stone, a solid piece of stone, and of course, if you've already put the decoration on and in the erection attempt the whole thing breaks, it's a lot of labor wasted. And so it's a very daring kind of operation. Whereas the pyramid of course is many small operations, many blocks over the better part of probably a generation. The obelisk is a single daring feat of engineering.

Question: Don't you think that they would have come up alongside of the river in order to allow the pullers have the room to move it and then do the hole under the stones supporting it by three stones or so? You could then build a boat or many boats under the stone and let it float out into the river and reverse operation into the end. ~Zoe

Answer: Intuitively we all feel that some kind of ballast and boat operation must have been involved in both loading the obelisk and unloading it. That is, where you use water, water seeking its own level. For example, Roger's idea, which didn't get very well illustrated in the film because of his problems with his little model sinking and so on, his idea was if you, for example, had a slipway and you brought the boat loaded with the obelisk into the slipway and the obelisk was loaded on these cross-beams, you could bring the boat in, put ballast on the boat so that you sink the boat down, the cross-beams catch on the edges of the slipway and, therefore, you've off-loaded the boat. You simply pull the boat out from underneath the obelisk. Roger wanted the obelisk to be loaded in a similar operation, but reversed, where you take balance lost off the boat, the boat floats up on the water until it lifts up on the obelisk on his cross-pole. When you actually try these things, there are numerous difficulties, and the boat boondoggle is something we want to re-examine when we go back to try to do an obelisk.

Question: Is there any symbolism involved with the shape of the obelisk? ~Mary

Answer: Well, there is a symbolism involved in the shape of the obelisk. It probably symbolizes the rays or shaft of the sunlight coming down. It's interesting, at the top of the hatchet's obelisk, she shows herself, Themoses III, giving gifts up. There's the inscription that the upper part of her obelisks were gilded with electrum, a combination of silver and gold. So basically, what you had is the top of the obelisk, where she shows herself in the company of the gods, gilded with blazing medal, so it was actually like the sun reflected off this electrum. So the symbolism of course is a shaft of light that reaches up to where any pharaoh is co-mingling with the divine beings. There's probably also... it's a little bit more convoluted and indirect, but there's also more a phallic observation relating to the sun God Othom.

Question: Instead of using pullers to have to work over their heads, why don't you use a technique called a Spanish Windlass? The rope is anchored at some strong fixed object. By then twisting a looped rope, a tremendous pulling force can be applied over the A-frame by a few people. ~Bernard

Answer: Well, Bernard, we did actually use a Spanish Windlass in Martin Isler's technique, not so much to pull the stone horizontally into an upright position, but if you look closely at Martin Isler's position in the film, he had Spanish Windlasses going off to either side of the obelisk, where the rope was twisted after it, was tied around the butt end of the obelisk, where it was parked in the turning groove. Isler used this to control the movement of the obelisk from left to right, that is, so that it would not move to either side as it was being lifted. So that, as it was being lifted, it was held firmly in place right on its pedestal, right with one edge right in the turning groove. To use a Spanish Windlass actually to move the obelisk horizontally or to raise it upright is an interesting suggestion. But it implies a very long, a very long length of rope, a lot of twisting, and some kind of a platform where all this can be carried out.

Question: How did you calculate the number of men needed to man the ropes? ~Grant

Answer: You know, I can't answer that specifically, because basically we left it up to Ali el-Gasab. Others have asked why we didn't use equations—how many men were needed to raise the obelisk and so on? Ali, who is no longer with us in this world because he passed away this last year, but Ali was literate, and he had worked with heavy monuments all his life, at least 40 years. He knew how to figure how many men he needed, and he had a specific way of calculating how many pullers were required and how many were required on the obelisk-side of the erection pit. Just exactly what his calculations were, I can't tell you, but we know that Ali was calculating.

Question: Why were there no women involved? ~Kathy

Answer: Well, actually, there were women involved. Cheryl Haldane, who was in the film, is an archaeologist from Texas A&M, and I'm not sure if the question is aside from Cheryl Haldane, why there were no women involved in our production, or why there were no women involved in ancient Egypt? Those are two different questions of course.

Question: Why not use a variation on hydraulics? If the ropes were fastened down, isn't it possible to wet them, tighten them, let them dry and shorten, place solid rock under the slightly lifted obelisk and repeat? After all, it's the desert. ~John

Answer: Well, you know, tricks like that, wetted ropes, dry ropes and so on, I wouldn't put it past the ancient Egyptians to have used any kind of technique such as John suggests. It was amazing to us to see how Ali el-Gasab's men tried anything and everything to get that obelisk to move, get it to tip and then get it upright. They tried rollers, they greased the rollers. It was very by crook or by hook. As I said earlier, Ali did much calculating, how many men he needed. As you saw in the film, he made a scale model of it, once the operation was under way, they just attacked with a ferocity and with a spirit that really has astounded us all. And anything and everything went at that point. Now, if wetting the ropes, allowing them to dry and wetting them again worked, they would have used it, any trick they could have used to get the job done.

Question: The process so far seems correct, however, I might suggest the use of timber braces anchored to the ground and lift the obelisk from the backside as we do in the "barn raising" method. ~Len

Answer: That's a very interesting suggestion. Not being Ali el-Gasab and not being the engineer on the project, it sounds good to me. I'd like to know more details.

Question: Did you try the counterweight idea that was suggested by the owner of the quarry? ~Jeff

Answer: No, we didn't try the counterweight idea that was suggested by Hamada, the owner of the quarry. It looked good. It looked good in his model. The problem with counterweight methods in obelisk raising or pyramid raising is you have to deal with the weight that's commensurate with the obelisk or with the heavy stone blocks in pyramid building, and it's almost as though you're doubling your operation, because somehow you have to get the counterweight way up there, too, in Hamada's method, in a height in its own sandbox, where then, when you release the sand, the counterweight sinks and you release the obelisk. So in counterweight, the methods for lifting pyramid stones or obelisks, you have to deal with the problems of getting the counterweight itself to a significant height so that it can then sink and raise it to the height that you want, raise and sink the weight that you want to raise. In both pyramid building and obelisks, you're kind of faced with the same problems, raising the original weights itself.

Question: Why didn't workers stand on the levers when they became too high to reach in order to utilize their weight to increase the downward force on the lever? ~Peter

Answer: Peter, that's a very interesting observation, and I've seen men do that. I've seen them climb up on to these heavy levers, stand on them. But we were using levers the size of railroad ties, although maybe twice as long. They were the same thickness as a railroad tie, and it wasn't just the fact that the levers were getting too high for the men to grab hold of, it was also that maybe six inches from their butt end, the levers are snapping like toothpicks. And this is a very sobering observation, because our obelisk is 40 tons. And yet, given the shape of obelisks, a 400-ton obelisk is not going to give you that much more room to lever, and you're not going to be able to use levers that are that much bigger, because men can't get ahold of them. So if our railroad tie-sized levers are snapping like toothpicks on a 40-ton obelisk on its point end, what's going to happen on a 450-ton obelisk, even if the men were standing on them? Of course it's not—it's kind of a precarious place to stand up on a lever. Even if they were standing on them, levering begins to look a little bit inadequate to the job of the very big obelisks that we know were successfully erected by the ancient Egyptians.

Question: What other obstacles did you and your colleagues face, not including the problems of transporting and testing? ~Aaron

Answer: That's a very good question. The film focuses on transporting and raising, and mostly on raising. One of the big problems we faced, which must have been a problem faced by every ancient overseer, was finding a big enough patch of granite where we could quarry an obelisk, even with modern means, without there being fissures and cracks in it. It was a hard job just to find a big enough patch of uniform granite that we could take out a 40-ton obelisk. Think how much they must have searched and done trial trenches and probes to find a good patch of granite where they could get a 400, 300-ton obelisk. That's just one problem. We spent many, many days, actually weeks, looking through the quarries to find a good patch of granite.

Question: Wouldn't a series of A-frames beginning at the top of the obelisk and being succeeded by a taller A-frame, as the first for the job and so forth, cement the levers that could be filling in the space behind the obelisk with rock and dirt to the point at which the center of gravity is over the base and the obelisk was standing by itself? Would this work? ~Lee

Answer: Well, Lee must be an engineer, because Lee has just anticipated what some of the engineers we've already consulted have suggested for Obelisk II, that with a series of A-frames you're getting a series of poles, almost like when you lever a heavy weight and you get purchase with your lever, you get some rise out of the load, you secure that rise by putting in rocks underneath it, then you get more purchase, more leverage and so on. This has already been suggested, a series of A-frames, and it's one of the things they're going to try in Obelisk II.

Question: Would it be possible to create a supporting cage-like structure at the bottom of the obelisk made from wood? This would have to be strong enough to withstand an impact into the bottom of the pit. Once in, with the extra angle while the men were pulling, it could be set on fire, a wood version of the sand pit. The only problems I see are the speed of the barn and how much heat the obelisk could withstand. Good luck. ~Sarita

Answer: That's an amazingly creative suggestion. I'm not sure what would happen in that case. One thing I would just note is that heat will spoil the surface of granite, and we showed that in the film, where Roger started dressing the surface of granite by creating a fire over it, and you see those big flakes pop off. So that's one thing you might have to worry about. You might have to worry about the heat creating cracks through the granite as well. Cracks are feared by every granite worker. Even our 40-ton obelisk, as we were pulling it out of the quarry, a very hairline crack appeared and every worker noticed it. Quarry owner Hamada went into a panic, and so I don't think he'd want to do anything, including heat, and the differential between heat and cold that would cause the granite to crack.

Question: It might be easier to slide the obelisk down a concrete ramp to the anchor stone rather than drop it, using sand and creating guess work. That way, a short, lightweight wooden test obelisk could be used to work out the proper alignment between the obelisk and anchor stone. It might also be easier to create a raised hill behind the obelisk so that the A-frame would rest above the obelisk. The pullers would be on the down slope of this hill. What do you think? ~Geoff

Answer: Well, the last part of Geoff's suggestion sounds like the kind of thing we were trying in a very cursory way at the end of the project with the A-frame. And it's a good suggestion. I do think that the pullers have to be on a ramp that's high enough and the A-frame has to be high enough that they're getting lift out of the pole, something that we've talked about in other questions.

Question: Could not triangular wedges in alternation—small to large, with the small making room for the large—be used from the rear to lift the obelisk? ~Tim

Answer: This suggestion of Tim's is really a good and very insightful suggestion. When we were doing "This Old Pyramid," we found that wedges were one of the most useful tools of all. We actually recreated ancient Egyptian wedges, where the ancient Egyptians put handles on the wedges. And there's nothing better when you've gotten a little bit of lift out of a three-ton block than sticking a wedge in, and you can stick a wedge in underneath to secure your lift, the lift you've gotten out of it when you have a handle on it. And also, when we were moving the obelisk that weighed 40 tons, the obelisk was so heavy it was literally crushing the rather thin rollers that we were using. One of the ways that the workmen would get some lift out of the obelisk is to get the pressure up off the rollers to pound in wedges with sledgehammers. Wedges are just marvelous little things, and it's a very good suggestion. I think it's something they probably used in an ad hoc way, not to raise the obelisk to its final height or to a height where they could pull it upright, but wedges are very powerful little tools and very handy for a lot of lesser operations.

Question: Weren't slaves used in Egyptian times to move the obelisks? ~Matt

Answer: Well, were slaves used? It is the case there was slavery in ancient Egypt. Mostly slaves were domestic slaves, though, in households. The image we have from biblical stories and so on, of masses of slaves doing great labor projects, is probably not very accurate. Or the image we have, for example, from the film "The Ten Commandments," where the masses of the Hebrew slaves are raising the obelisks and doing other tasks is probably not accurate. There were specialists who were involved in these operations, but it is the case that prisoners of war could be assigned to working the granite in Aswan. And we do know that being sent to the granite was a punishment for various kinds of crimes. When it actually comes to raising the obelisk and pulling it, they probably would not have assigned that operation to slaves. Slaves would more have been involved in the quarries for shaping the granite, that very hard, pounding work. The actual raising of the obelisk, when it was successfully quarried, after it had been successfully transported to the religious capital, and after it had been decorated with its hieroglyphs, was certainly not entrusted to people who were enslaved, it was probably entrusted to specialists and workers who had the same kind of spirit that our men showed from Aswan and Luxor.

Question: When are you going back to Egypt to try this again? ~Becky

Answer: Well, the plans now call for us being back in Egypt with another team down in Aswan in February and March for our second attempt of raising the obelisk, using ancient Egyptian tools, techniques and operations.

Question: Were the pyramids built at around the same time as the obelisk?

Answer: No. In fact, the gigantic pyramids that are most popular in most people's imaginations were a good 1,200, 1,300 years before the giant obelisk was raised. That shows you how long Egyptian civilization lasted. The pyramids belonged to the Old Kingdom, and the obelisks belong to the New Kingdom. In between Tutankeman and the pyramid of Kufu is more than 1,200 years.

Question: Did your experience trying to raise the obelisk, but failing, give you any ideas about how to do it better? ~Karl

Answer: Yes, it gave us many ideas about how to do it better. For one thing, if we had had a higher ramp which is to say a deeper turning pit, we would have gotten more lift from the tipping operation. That is to say that when we brought it over the edge of the ramp and tipped it down into the pit, and then slid it down that one side of the pit down to the turning groove, if our ramp had been higher on that side we would have gotten more lift out of the tipping operation. If the ramp had been higher on the other side, we would have gotten more lift out of the pulling. And if we'd used an A frame and the ramp had been higher on the other side it would have achieved more lift as well.

Question: Have any obelisks ever fallen over? ~Mary

Answer: Of a series of obelisks that once stood in the great Karnak temple, eight or nine must have fallen over or have been removed. Engelbach, the British engineer who wrote the major study of the unfinished obelisk at Aswan chided the ancient Egyptians for not having better foundations underneath the pedestal on which the obelisk sat and he blamed this for some of the obelisks having fallen over. In addition to obelisks of course being forcibly removed, like the one in front of the Luxor temple that was the mate to the one that still exists, a whole number of obelisks must of fallen over (about eight or nine). It's thought that one of the principle reasons they fell was earthquakes and not so much the bad foundations that Engelbach pointed to. We know that there's been at least one earthquake if not more that caused considerable damage in the Karnak temple, not just to the obelisks but to the giant pillars and architrazes.

Question: How was the bottom side of the obelisk (attached to the quarry) freed from the granite? ~Angela

Answer: The first question we know the answer to with a fair degree of probability because we have spines of—if not obelisks—long granite blocks that have been snapped off. The evidence from the quarries is that just as they channeled around the obelisk simply by pounding the granite to create these separation trenches or channels, so also they channeled in underneath. That must have been a really difficult operation. It was difficult enough for workers to sit in the trench pounding all day as narrow as it is (as you saw in the film), but to actually start pounding the face of the granite in underneath the obelisk to free it up must have been really difficult, but that seems to be what they did. When the two sides came close enough so that there's simply a spine of natural rock still attached, then they got great levers and probably levered from one side to snap the obelisk off that spine. The evidence is that there are spines that exist in the quarries where they've snapped off blocks after channeling in and under them from both sides.

Question: A smaller version of the obelisk had been raised by draining sand from underneath it. If there were stops in the movement of the obelisk, such as poles placed in layers through the sand, wouldn't that solve some of the problems in positioning the obelisk at the right point to meet the turning groove? ~Stacy

Answer: Stacy, you know that might. In all fairness, we didn't do a completely fair test of the sandbox method. The sandbox idea was first suggested by Engelbach, which as you know, weighs about 1168 tons. Engelbach's idea was not that it would be a box, but that it would be more like a funnel. And the bottom of the funnel would be the same size as the base of the obelisk itself so that the obelisk would have nowhere to go but down to that base. It wouldn't be able to get askew and stuck like it did in Roger's sandbox. The sides of the funnel would have been sloping and smooth, and I don't know that you would have needed stops. One of the main problems with Engelbach's sandbox or sand funnel is that the obelisk would get stuck even more than it did in Roger's sandbox. Of course then, you also have the problem, as Hamada pointed out, of men underneath the very heavy obelisk, 450 tons or whatever, taking the sand out. Our sandbox, anyway, in the film, was not a completely true test of what Engelbach was suggesting.

Question: Somebody recently proposed that the ancient Egyptians might have harnessed wind power to raise obelisks, using giant airfoils or kites. What do you think of that notion? ~Rosemary

Answer: I don't think it's very likely that the Egyptians harnessed wind power to raise obelisks. There's no suggestion in the historical or archaeological record that they created such contraptions or that they had the technology that would have been required for aerial lifting devices like that—something powerful enough to raise something as heavy as 300 or 400 tons.

Question: The same small canal that was built to float the stone to the site could be used to fill a large pool that is built higher as the water level rises. Animal skin bladders attached to the obelisk would gently float the stone upright. This method would "baptize" the stone in the holy water of the Nile as well as provide an aqueduct and reservoir for the workers and city. It's just a theory but it seems plausible. ~Dustin

Answer: It was probably beyond the Egyptian's hydraulic technology to have a series of locks that would raise the obelisk on water or just raise the water itself as high as they needed to get it to set it upright. Water lifting was always very limited in ancient Egypt from the known evidence. In the Old Kingdom pyramid age, water lifting was by means of shoulder poles with pots slung over the pole. By the 18th dynasty, by the New Kingdom, that is by the time of obelisks they could lift water with something called a chaduf which is a huge lever with a water receptacle on one end and a counter weight on the other. By that means, they lifted water from canals into fields so that they could be perennially flooded. But a system of locks like those that pass ships through great canals like the Panama canal or through the barrages in Egypt today were probably beyond the means of the ancient Egyptians. The water displacement would also have to be significant to float that obelisk and that's a factor in how they transported it on the boat but to do it with animal hides you'd have to have considerable displacement and it's very unlikely that they had those means so that they did it in that way.

Question: How did 400 tons of granite get on to the sled? ~Adam

Answer: This question reflects one of those operations that we tend to overlook when we launch into programs like building pyramids and raising obelisks, trying to replicate the ancient Egyptians' technology. It is indeed very difficult as we found out in "This Old Pyramid" to load a sled with a block of stone weighing many tons. The first time we tried this we rolled a stone over to the sled and then onto the sled but because it didn't land on the sled on dead center, it actually pushed the sled down into the sand and the sled was sticking up into the air and the stone of course was chewing the wood and splintering it. So how you load something like 400 tons or 456 tons, the weight of the heaviest obelisks that we know (other than the unfinished ones) onto the wooden sled is a very good question and it would be excellent to try to replicate that in our next shot at doing an Egyptian obelisk. One idea is you could tie the sled to one side of the obelisk, so that the obelisk is firmly lashed to the sled and then you could simply turn the whole assembly, sled and obelisk over very carefully and slowly by levering. But it must be a delicate operation to do that with so much weight and not to completely crush and splinter the sled.

Question: I'm just curious why an engineer was not included on the erection team. In 30 minutes I calculated all the forces and geometries necessary to raise the obelisk using sophomore level engineering skills. I estimate that with two wood structures (similar to the one used in the team's last ditch attempt) and a platform capable of supporting 1/4 the obelisks weight the obelisk could be lifted with between 150 and 300 men (assuming each could generate a pull equal to his weight). The Egyptians are famous for their fantastic engineering feats. Isn't it foolish to try to duplicate them without extensive knowledge and understanding of the field? ~Dan

Answer: Our purpose was not to test how we could raise an obelisk, or even how sophomore-level engineering math would help us raise an obelisk, but how the ancient Egyptians might have done it. Now it may be in fact that they had engineering and that because we didn't have engineers on the team we were ignorant of engineering skills and calculations that the ancient Egyptians might have done. In our next attempt we still want to stick to the task - not of completely replicating an ancient Egyptians obelisk project (cause we can't do that without replicating the entirety of Egyptian society) but we'd like to once again try out particular tools, techniques, and operations like loading a sled, like the tipping operation, like raising it up on its pedestal. But we will have, in addition to hands-on know how, an engineer on the project. So we will always be checking that the engineering skills we bring to bear when we're testing a particular tool, technique, or operation are not exceeding the bounds of what was available to the ancient Egyptians.

Question: Are there any ancient records at all, however obscure or fragmentary, on how obelisks were raised? ~Antonio

Answer: We have no manuals for obelisk erection in ancient Egypt. And there are no explicit scenes showing all the workmen that would have been required to raise an obelisk. What we do have are symbolic scenes of the king raising obelisks, because in a sense all these assembled people and all these workers were an expression of the king's personal body and might. So rather than showing all the workers doing it they show the king doing it and then of course it's just a symbolic representation; the king has a rope around the obelisk and he is ritually pulling it up. It looks very easy of course because the king in fact in such scenes is nearly as tall or taller than the obelisk that's shown. We have the Ansatasi Papyrus where one scribe chides another one about his level of skill in figuring out various kinds of operations, one of which is raising a colossal statue of the king (not an obelisk), but it makes some kind of an obscure reference to compartments containing sand which is why those who favor the sandbox method point to this. But aside from that Papyrus and the symbolic representations, what we're left with is the evidence on the ground in the way of the obelisk bases, the turning grooves, the evidence of the unfinished obelisk in the quarry and the evidence of the obelisk that is still standing in Egypt from ancient times.

Question: Is there any danger that when you manage to tip the obelisk into its upright position that it will topple over the other side from its momentum? ~Howard

Answer: Yes. One of the things we did not learn from our experiment is whether, even if we had successfully raised that obelisk, it would have stood. When we quarried the obelisk from the quarry using modern means, it was a bit banana shaped and one of the things that must be required for an obelisk to stand upright successfully with no attachment, simply standing on its own is that it be plum - that is that the vertical axis of the obelisk be straight and that the center of gravity in that direction be fairly centered within the body of the obelisk so that the weight isn't distributed to one side or the other. The other point is that the vertical axis of the obelisk has to be fairly perpendicular (I would imagine) to the base. Now the base of an obelisk is fairly small. If you have bumps and dimples in the base of the obelisk, it's going to make it unsteady. So all those conditions have to be met and the interesting question is, how did the ancient Egyptians quarrying the obelisk by means of channels that they were pounding out and then pounding it under and snapping it off at the spine, during all of that how did they achieve an obelisk that met all of these specifications.

Question: Did all the effort that went into building these massive monuments, like the pyramids and the obelisks, use up so many resources that it was detrimental to society? ~Jack

Answer: No, probably not. Certainly not with obelisks. By the time that obelisks were set up Egyptian society was populous enough and complex enough that raising the obelisk and quarrying it and transporting it and then raising it was really probably drawing on a large number of workers and resources but not so many that it was actually a drain on society. Of course the pyramids are different, especially the gigantic pyramids of the early part of the pyramid age, like the pyramid of Khufu at Giza. It's so huge that it must have drawn on resources nationwide. But an interesting possibility is rather than it draining resources, it actually had a nation-building effect for Egypt because it was a socializing process where people were brought from villages and communities throughout the land to the center where they saw this Cecil B. De Mille epic of hundreds, probably thousands of people working on this common project. And the evidence we have is that most of these laborers were seasonal and they worked for a certain stint, a certain period of time, maybe a month, and then they were spun off and replaced. Certainly there were skilled workers who were there permanently. But to come into such a labor project, to see instead of a few hundred people in your village thousands of people, to be part of a nationwide project, and then to be spun off again and return to your home - it must have been a very powerful socializing experience. And rather than it being detrimental to Egypt as a nation it actually may have helped build Egypt as a nation.

Question: It seems like working on a project like raising the obelisk or building a pyramid would be, while hard, very rewarding. Can you think of any projects today that would generate a similar feeling? ~Mary

Answer: You know, it's hard to think of projects today that would have a similar feeling, because society is totally different today than it was then. One of the most revealing operations in NOVA's ancient technology series, I think, is the Incan bridge-building operation, where the different families go out on the hillside and they pick grass and they weave their grass into segments of twine, and the different families combine their segments or lines of twine into rope, and on the day of building the bridges, the different families combine their rope into big cables that the different villages donate to the bridge, so that the bridge is really an intertwining or an interweaving of all the different families, households, and villages of that particular culture. There's some evidence that in ancient time, monuments were built the same way, and that pyramids in ancient Egypt were built by the turning out of labor from teams from different communities. So when they actually raise something like an obelisk, not only did you have the enthusiasm and the excitement that we had from teams from Luxor and a whole other team from Aswan chanting and celebrating, but you had teams from all over the country.

Question: What is the significance of the writing on the sides of the obelisk? ~Jen

Answer: Well, the writing varies. For the most part, it is the names and titles of the kings who raised the obelisk. Kings have five different names and various titles, and so that's by and large what would decorate the sides of the obelisk, as well as images of these kings giving offerings to the gods. As I said in an earlier question, the obelisk kind of raised the king's image up into the heavens, and being gilded with a combination of gold and silver, called Electrum, and that blazing in the sun, the king's image is literally combined with the images of the gods up there in the sky as well as the King's names, all aglow and glittering in Electrum. Hatshepsut, on her obelisk, added something else. She added the whole story of how she sent a team out to quarry the obelisk, transported, raised it at the temple of Amman; that's in addition to her story about how she went about raising these monuments.

Question: When you go back, how many methods will you try? And will you have the same amount of time and other constraints as you did last time? ~Gene

Answer: Well, we don't know for sure yet. We're still in the process of talking about that. It would be nice to try to do a little thinking so that our attempts to replicate an ancient Egyptian operation are not constrained by a modern film and production budget and time schedule, so that we at least give ourselves enough time to try one or two or three things as thoroughly as possible. One of the things we'd like to try in the future is not just different ways of raising the obelisk, we'd actually like to try to construct some kind of a boat that would test how they might have transported the obelisk down the river of Aswan.

Question: Did working on this experiment make you feel at all like you were able to get inside the minds of the ancient Egyptians? ~David

Answer: Well, that's a good question. I'm not sure we can get inside the minds of the ancient Egyptians, but let me tell you that whatever the thoughts may be of popularizing ancient technology by trying these replications of tools, techniques and operations, whatever shortcuts we might have to take for a modern, popular film production, nothing beats actually getting your hand on limestone blocks that way, two or three tons in building pyramids. We're actually getting face to face with the granite in raising an obelisk. That's one of the real values of these productions. In the film on obelisks, you saw a bunch of men down in that trench that actually defined and separated the unfinished obelisk. Until you actually get down in that trench with a dolerite pounder that weighs five kilograms, and you just for a few minutes swing it up and down with your arms, you can't appreciate what human labor really went into creating the monuments we see all over Egypt. We didn't get so much in the minds, but we saw the physical bedrock reality that they had to deal with—what motivated them, what gave them their spirit of accomplishment, what gave them the spirit that we saw in the men from Aswan and Luxor who worked for just three weeks on this project.

Question: What do you think accounts for people's fascination for all things Egyptian, especially the pyramids? ~Francesca

Answer: That's one of the most profound and difficult questions that anyone could be asking. I've worked with the monuments of ancient Egypt for 25 years now. I've spent years and years with the pyramids, I've lived in Egypt for 13 years straight before coming back to the United States, and still I don't know the complete answer to that question. There's something about ancient Egypt that has a pull on everyone in the modern world, not just Americans, the Europeans, Japanese, people worldwide. Various answers that I've tried out and worked to some extent, but aren't completely satisfying, include that the Egyptians were terrific designers. Something about the way they depicted the human being, pyramids, the temples, the obelisks, they were just great designers in an architectural sense.

I think also part of the attraction of ancient Egypt is that it's so very old. It's one of the earliest civilizations on our planet. And it's so very big. Everything they did in their monuments is big. The pyramids, the obelisks, the temples, the statues, and they were able to do these very big things because they had easy access to hard and soft stones, limestone, granite, other kinds of stone. And so they could build these colossal monuments in stone that survived the ages. Whereas other civilizations, like the Sumerians, built in mud brick, so we don't see their accomplishments as much.

Even in ancient times when the Greeks and Romans came to Egypt, they were astounded by these skyscrapers. It's as though you walked into Manhattan or something for ancient times. These days, as civilization races towards some kind of a future, we're not sure what, with such dramatic changes over such short periods—automobiles, skyscrapers, computers—I think we're filled with a lot of anxiety as to where we're going. I think when we look back to times over the horizon, when we feel a little bit lost in our own civilization, there's something very appealing about this lost ancient Egyptian civilization. Maybe we're looking for some kind of an answer for what we're going through now. It's hard to know. There's no quick easy answer to that question.

Question: Do you know if there are any obelisks in private collections? ~Jon

Answer: Well, if there are obelisks in private collections, I don't think they're as big as the biggest obelisk that Ramses II made. I don't think there are any obelisks hiding in private collections anywhere. Obelisks started out as very small monuments. Some of the oldest obelisks we know about are about knee-high. They're made out of limestone and they were put in front of the tombs of prominent households in the Old Kingdom, noblemen and so on. There could be small obelisks like that that could be in private collections.

Question: When did the society that was responsible for building the obelisk come to an end and what caused its downfall? ~Maura

Answer: The society that was responsible for building the obelisk was that of ancient Egypt. One easy way to think of this is that ancient Egyptian civilization lasted from 3000 B.C. to 30 B.C. That's about when Cleopatra IV died. However, the heyday of obelisks was in the 18th Dynasty, Egypt's age of greatest empire, and that came to an end about 1000 B.C. So the empire gradually dissolved. Other great powers were on the rise, the Assyrians and later the Persians and of course the Romans, and just exactly why it fell into demise is a complicated question. It's one of the kinds of questions that archaeologists write Ph.D. dissertations about.

Question: Do you think the Egyptians knew that the granite was extremely durable and chose it for that reason or was it just the material they had available to them? ~Marc

Answer: No, Marc, they certainly knew that granite was durable. As a matter of fact, granite probably had a very definite symbolic magical significance for them. Just why the different kinds of hard stone and soft stone that they built in were chosen for various monuments we aren't sure. There's enough to suggest, though, that there were magical reasons that we're missing, that granite had a definite magical purpose, as did alabaster, limestone, and the black granite and other hard stones like dolorite. So there was probably a symbolic reason for the stone that was chosen.

Question: Why was the obelisk seated into the turning groove at a 32-degree slope? Was it because the breaking system was not adequate? Solve this problem so that you can begin the raising from a 45-degree or greater start point. Now, how about some camels, oxen, horses, or elephants for some real power? Good Luck, and Aloha from Maui!!! ~Gregory

Answer: Yeah, OK, you�re right. We should have had the obelisk at more than 32 degrees. Next time we hope to have it more like 45 or even steeper. And we recognize that that's one of the problems. We'll try to correct it next time. Camels and elephants are out, because the ancient Egyptians didn't have camels and elephants. But they did have oxen, although probably in a delicate operation like moving the obelisk they would have not have entrusted it to oxen, they would have used manpower.

Question: It seems to me if you can not pull the thing up why do you not just push it up? I would tend to think that if you applied force to the other side of the obelisk it could possibly go up easier than if you pulled on it from the side you are. By the way I loved the sand trap ideas. ~Craig

Answer: I'm not sure what Craig means by pushing it up. It depends on how the obelisk comes in on the other side, the opposite side from the pullers. If it comes in lying down or nearly lying down like Martin Eisler had it, then you can't push it. It's a question of lifting. And even if it comes in at a 32-degree slope or so, the way we did the big obelisk in the film, it's still a question of lifting, not pushing. And the lifting, of course, has to be done with levers. So I'm not quite sure what Craig means by pushing.

Question: The ancient Egyptians were the most prolific stone movers in history. Is there any written history on how they may have moved massive stones over large distances? I remember seeing a show on TV where the stones were set in place by dragging them over a hole filled with sand, the sand was then removed through an access tunnel, and the stone was slowly set in place. The effort required (by any method) to move the Stonehenge stones over a 20-mile distance would have negated any method of raising them that would have been considered a gamble. Although your system worked, I believe the stones were set into place with some type of dampening agent to ensure that the stones were not damaged. What do you think? ~Lowell

Answer: Is there any written history on how they may have moved massive stones over long distances? The only depiction we have of moving a very massive weight any distance is from the Middle Kingdom, the 12th Dynasty: a tomb of a man named Jahuti Hotep. And there is a scene in his tomb, or there was a scene, it's very badly damaged now, of, I believe it's 172 men pulling a very heavy, large, colossal statue. The statue is estimated to have weighed 54 tons. So you have long lines of men going off in different ropes. That's the only scene depiction we have. We have text mentioning people who went to quarries to get stones for pyramids, stones for obelisks, stones for monuments, and in a number of cases we have specifications of the boats that were built. I think there's a man named Aneni who went to fetch an obelisk for Thutmoses I, and he records, I believe, the construction of a barge to transport it, that's about 3/4 the length and width, that is the width is about 3/4 the length. And so we have inscriptions like that, but nothing real detailed.

Question: What is the estimated time (months, years) that it took the ancient Egyptians to erect an obelisk (e.g., the largest one), from the first chip in the quarry to the final touches of the upright piece? ~Jon

Answer: Hatsupsut records that it took her seven months to build her obelisk in Karnak. I believe that would be the pair of which one is still standing. And if I recall correctly that is the total time she says it took to quarry, remove, transport and raise the obelisk, seven months.

Question: Rather than using a ramp composed of two straight sections, why not use a parabolic curve in the second part of the ramp? The parabolic part might help move the obelisk around since the contact surface is reduced (though you'd need a much stronger sled) and as the drop rate could be controlled, it gives a better chance for the obelisk not to break upon landing on the base. Furthermore, that might help position the obelisk closer to vertical—then it would be easier to pull to its completely vertical position. What do you think? ~Steven

Answer: A parabolic curve, indeed, would reduce the amount of contact between the obelisk and the ramp down to the pedestal. But it probably would have been a bit difficult to construct that parabolic curve out of mud brick, for example, or stone rubble, or mud brick compartments filled with stone rubble and debris, or filled with sand. And it's unlikely that they would have built in stone simply to create a parabolic curve, since most of the materials they used for secondary constructions, like ramps and embankments and so on, were mud brick and debris.

Question: How did the Egyptians make the giant mounts of dirt? ~John

Answer: Well, they probably transported most of the material simply with men carrying baskets, the way workers carry dirt on excavations today. It may seem astounding that they could have carried enough debris, sand or dirt, for making these huge embankments and ramps and so on. But in fact, that's what they did. And they did it on a regular basis, not only for raising large monuments, but for creating the dikes and canals on which Egypt's irrigation, agriculture depended. So they were very used to moving dirt, which they did for their basic infrastructure all the time.

Question: My husband and I sail a 42-foot sloop. On our mainsail, we have a multiple-block system that allows me (at 130 lbs.) to adjust our mainsail with one hand. The Egyptians were accomplished boaters. Is there any evidence to suggest that the Egyptians may have had similar technology? If so, could you use it with your A-frame structure to lift the obelisk? ~Heather

Answer: I believe it's very true that there should be important clues in their nautical technology. I, myself, am not a boat person. So I'm not totally conversant with a multiple block system, which is what Heather is suggesting. But the A-frame, for example, that's been suggested as a gaining, as allowing the Egyptians to gain a mechanical advantage in lifting the obelisk, the A-frame and the way it operates may have been very similar to the way we see masts operating on early boats, which are very narrow kinds of A-frames, in fact. It's not a single piece. It seems to be two pieces, with cross pieces like a very narrow A-frame. And I think the end plate is a very good one, that the way they raised these heavy masts and other aspects of nautical technology probably holds clues as to how they did heavy weights like obelisks. In our next production, we hope to be having not only an engineer, but also an ancient boat specialist on the scene. Not just to try various ways of transporting the obelisk on a boat, but maybe also to give us insight into lifting operations, as Heather suggests, on land, for raising these heavy weights.

Question: Weren't a lot of obelisks put up two at a time? If so, then couldn't a lowering platform for one obelisk be used as a raised level workman platform for the second obelisk? Efficient use of mud-brick with no need for A-frames. ~Dennis

Answer: Weren't a lot of obelisks put up two at a time? Well, whatever ramps and embankments they used for raising one obelisk probably were used for two when the obelisks were put up in pairs. And quite often they were. In our operation we had a great pit between two ramp sections. And the pit—of course at the bottom of the pit, you had the base of the obelisk. And the pit was for the tipping and then raising operation. They would have had to move the pit, obviously, or else had two pits, but that was no problem. They could have filled them in. So yes, indeed, they could have built one great ramp embankment system, sloping up from both sides, or to either side of the temple pylon, with this great entrance. And when they wanted to, they probably would have had to have raised the obelisk then in sequence, doing the farthest one first, putting it down into its pit, if that's the method they used. And then there it stood, you see. And then the other one from the direction that the obelisks were being brought in, would have been brought in and set up. Obviously, you couldn't have one obelisk standing and being in the way of the other one. That would imply that if they did use one ramp embankment system, it also suggests something about the order in which the two obelisks were put up.

Question: I have a book called "Babylon Mystery Religion—Ancient and Modern" by Ralph Woodrow that includes a chapter on obelisks. On chapter five, page 34, the obelisk at St. Peter's Square at the Vatican is depicted in an old drawing being raised inside an elaborate giant scaffold-like structure surrounding the obelisk lifting with ropes from the top. I can't tell, but pulleys, which certainly increase the mechanical advantage, may be at the top of the structure. Would this technology have been available to the Ancient Egyptians? ~Chris

Answer: There is some evidence that the Egyptians had a pulley-like device as early as the Middle Kingdom. Whether these pulleys would have been useful in moving heavy weights like obelisks is doubtful, because as Roger Hopkins points out, a pulley is a wheel, and the wheel is only as good as its axle. And until you have iron and steel you just can't get a strong enough axle to have a pulley taking and distributing weight on the scale of 400 and 300 tons, which is what the largest obelisks weigh.

Question: Could the structures shown near the obelisk have been used to erect them? A drum connected to the nearby structure could be used to wind up a rope, thereby lifting the obelisk into position. This would require the technology of turning the drug (or roller) as the method of propulsion (like a come-along) instead of pulling the object with ropes and using the rollers only as a way to reduce friction. Did they have this technology? ~Ed

Answer: While it's been suggested that the structures near the obelisk might have been used to erect them, some people have suggested in fact that the temple pylons, the great front wall of the temple that stood right behind the obelisk, or in front of which the obelisks were raised, that that pylon could have been used as a lifting platform for ropes and men. The problem is that the turning grooves aren't on that side of the pedestals of the obelisks. The turning grooves are usually perpendicular to the front of the temple, so that the obelisks were brought in alongside the temple, front temple wall. It's probable then that none of the giant statues or the front wall of the temple was very useful in raising the obelisk—that temporary banks, embankments and ramps would have been used.

Question: Do you believe the ancient Egyptians saw the obelisks as holy? Also, as I watched your show someone said that the ancient cities were built to last through eternity. What was the logic behind that question? Did the Egyptians actually believe their empire would last forever? ~James

Answer: Well, did the Egyptians believe their empire would last forever? Yes, they did. They expressed that wish again and again. They believed their empire, their temples, the great Karnak temple and these obelisks would stand forever. They had two words for "forever." One was djet, which means permanently forever. And the other is Neheh, which means continuously forever, for all the cycles of time. In other words, forever and ever. Now I mean somebody who might have been a skeptical person in ancient Egypt might have wondered if in fact that was the case. And we do have some skeptical literature from the ancient Egyptians themselves. Once their civilization had lasted from 2,000 years or more, they began looking back and seeing some of the earlier structures that their ancestors had built already in ruins. So they weren't dummies. They could see that things fell apart. It's an interesting question though, because we could ask it about ourselves. Has any of us thought whether the World Trade Towers in New York City are supposed to last forever? What is the planned obsolescence of a skyscraper? What is the planned obsolescence of say, Manhattan or downtown Los Angeles? Do we think these things will last forever?

Question: Make an A-frame, put the crossbar 3/4 of the way down. Then attach ropes to the obelisk (at the top) and to the A frame (at the top). Now attach more ropes to the crossbar, have your volunteer crew pull these. This will increase your leverage and multiply your pulling power 3 times. This should be more than enough to right the obelisk. (name withheld by request)

Answer: Well, we certainly believe that there are many more possibilities with either one or multiple A-frames, and that we can in fact, increase our leverage and gain a greater mechanical advantage. And that's one of the things that we're going to be trying when we go back to continue to try to raise the obelisk.

Question: Could the wooden support that the obelisk rests on, as it is dragged to its resting point, have wheels at its base (somewhat like a dolly), so when it is in the tilting slot or groove, it would be easier to put upright (like our arm and elbow), then when it's in position, burn the support dolly at the same time making settling adjustments. (name withheld by request)

Answer: Well, here we have a suggestion about wheels again, that maybe it could have been on some kind of platform and then it was wheeled into place. Once again we come back to the notion, as we were talking about with pulleys. A pulley is a wheel, and it's like all wheels, the wheel is only as good as its axle. And in order to carry really heavy loads, wheel systems like great semi-trucks and so on, have very powerful axles, to say nothing of their engines, and so on. But the axles and the frame of a flatbed truck, a mach truck or a semi with very heavy weight—they're very powerful. Of course it's made out of hard iron and steel. Without iron and steel it's hard, I believe, to make a wheel system that will carry a heavy load. That's not to say the Egyptians didn't have the wheel. They certainly did. It's just that it was not adaptable to carrying very heavy loads, because they did not have that, they were not that fluent in the use of iron, and certainly they did not have steel. Iron really comes in in a big way about the 26th Dynasty. That's the earliest that it's there in a big way. We have examples of iron before that. So iron is not really there, prevalent much before say 525 B.C.

Question: I think if they used a column or wheel of significant weight to roll down a ramp a precise distance and speed with said wheel or column winding up pulling ropes as it travels. I think diameter of wheel plus weight of wheel plus angle of said ramp, plus using A-frame would lift obelisk. ~Marc

Answer: Marc is talking about a wheel again, but I think it's a slightly different suggestion. It's not so much a suggestion of using a wheel with an axle. But another idea is to make heavy stones themselves wheels of sorts by putting wood pieces against the sides of the stone block for example, the wood pieces being rounded so that when you put four of them around four sides of a block, you actually created a wheel out of the block, and then you can roll it along. I mean that's more feasible with stone blocks for pyramids, but probably not feasible at all for a long tapering obelisk. I'm not sure if that's what Marc is suggesting, but it reminds me of that suggestion at any rate.

Question: I would like to throw in my two cents about how to float the obelisk. Did you forget that the Nile is only recently the victim of human flood control? Ancient solution: build a drydock on the flood plain. Tie a barge off atop the drydock. Load the obelisk during the dry season. Wait for the floods—float away. Tie up at a similar facility down river. Wait for waters to recede. Unload the obelisk. Stone/rock piers aside the drydock would help in on/off loading. ~Saxon

Answer: Well, we're back to that suggestion we were suggesting earlier about building a drydock on the flood plain. And I think it's a very good suggestion. And it's something that it would be nice for us to try. In order to try this, since the Nile basin of which I spoke, the flood basin that held the water for six to eight weeks out of every year when the Nile flooded its banks, these basins no longer flood. The dikes and levees of course are no longer in repair because just the high dams, the Egyptian Nile Valley no longer floods. So in order to test this idea, which I think is a good one, we'll have to create our own drydock in our own little basin and somehow try to have it flooded. It could be a whole operation involving pumps and so on. We'll see what we can do when we get back to Aswan.

Question: On the show, the obelisk is left unraised. Was the obelisk ever raised? The show is several years old; have there been any new discoveries that show how the ancients raised a 400-ton obelisk? (name withheld by request)

Answer: Will the obelisk ever be raised? I don't know that there have been any new discoveries about how they raised obelisks. The interesting thing is that most of the theories were already on hand before we did our show. It's very rare, if ever, that people have done the kind of experimental archaeology where you actually go out and pull these heavy weights and raise them and so on. I'd like to emphasize again that in the shows, this whole pyramid and obelisks that we did with the ancient technology series with NOVA we were not doing 100 percent replications of ancient pyramid building or obelisk raising. We were trying specific tools, techniques and operations to gain greater insight and I think we did. I don't think we can actually make much progress on new theories without that kind of experimentation. Nobody has ever tried to raise an ancient Egyptian obelisk using the ancient tools, techniques and operations before. And I know that they haven't done it since, or at least as far as I know no one has. That may be one of the reasons why there have been no new insights in the few years since we did the obelisk film. Our hope is that we'll come up with some new insights and possibly even some new theories when we go back to Aswan and give it another try.